The fire is threatening residents in a large area of rural land which includes the Greenbushes townsite and Dalgarup.

Residents of Greenbushes, Hester Brook, Wandillup, Maranup and Southampton have been advised to leave if it is safe to do so.

Those in the Shire of Bridgetown-Greenbushes are being told to place a green bag on their mail box or gate to advise firefighters they have left.

A watch and act warning remains in place for residents in the Kin Kin area.

Authorities have held an emergency meeting for residents at the Bridgetown recreation centre, which is also the relocation point.

Other fires also sparked by Tuesday's lightning are currently within containment lines, but conditions are hot and dry with variable winds meaning the situation could change rapidly if they break lines.